1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), and more particularly, to an apparatus for driving various types of thin-film transistor liquid-crystal display (TFT LCD) panels having different specifications.
2. Description of the Related Art
Generally, a TFT LCD driver for driving a TFT LCD panel includes gate drivers for driving gate lines (or row lines) of TFTs and source drivers for driving source lines (or column lines) of TFTs. When the gate drivers activate the TFTs by the application of a high voltage, the source drivers apply source driving signals to the respective source lines for displaying colors, and, as a result, a color picture is displayed on the LCD.
However, the characteristics or driving methods of a driver integrated circuit (IC) such as a gate driver or a source driver, and the characteristics, size and resolution of a panel vary from one LCD manufacturing company to another, and even between LCDs produced by the same company, that have different product specifications. Thus, the timing of a control signal for a LCD panel or a driver IC varies, depending on the product specifications of the LCD panel, and controllers for panels and driver ICs have been manufactured as application-specific integrated circuits (ASICs), resulting in numerous diversified panels or driver controllers.
FIG. 1 is a block diagram of a conventional LCD panel driving system. Referring to FIG. 1, the conventional panel driving system 100 includes a graphics card 110, a display unit 170 including a panel 193 for an LCD, and a panel driving apparatus 120.
The panel driving apparatus 120 receives composite data DATA_S including color data and vertical and horizontal synchronization (sync) signals (not shown) from the graphics card 110, converts the composite data DATA_S into a suitable form for the specifications of the panel 193, and transmits a converted composite data DATA_SS to the display unit 170. The panel driving apparatus 120 includes a microcontroller 160, a data converting portion 130 controlled by the microcontroller 160 for receiving and converting the composite data DATA_S and generating a converted composite data CDATA_S and a clock signal CLOCK, a scaler 140 controlled by the microcontroller 160 for scaling the converted composite data CDATA_S, and a transmitting portion 150 for receiving an output signal SCDATA_C and the clock signal CLOCK and transmitting the converted composite data DATA_SS and the clock signal CLOCK to the display unit 170.
The display unit 170 includes a receiving portion 180, a timing control portion 190, and the panel 193. The receiving portion 180 receives the composite data DATA_SS and the clock signal CLOCK transmitted from the transmitting portion 150, and transmits the received composite data DATA_SS and the clock signal CLOCK to the timing control portion 190. The timing control portion 190 applies control signals CSG suitable for the specifications of the panel 193 to the panel 193 to drive the same. The panel 193 is driven by a source driver 196 and a gate driver 199.
In the conventional panel driving system of FIG. 1, the panel driving apparatus 120 receives the composite data DATA_S from the graphics card 110, scales the composite data DATA_S according to the specifications of the panel 193, and applies the scaled composite data to the display unit 170. Here, the specifications of the panel 193 are classified according to panel size and resolution, and panel driving methods of drivers. The timing control portion 190 of the display unit 170 applies the control signals CSG according to the panel specifications to the panel 193.
However, since specifications greatly vary from one panel to another, the timing control portion 190 is limited to applying control signals CSG to the panel 193 that are compatible only with panels of like timing configuration. Since the timing control portion 190 is manufactured as an ASIC. Manufacture of the timing control ASIC in compliance with a variety of panels having different specifications, would cause the manufacturing cost of the LCD to increase.
To address the above limitations, it is a first object of the present invention to provide a panel driving apparatus for a thin-film transistor liquid crystal display (TFT-LCD) applicable to a variety of panels having different specifications.
It is a second object of the present invention to provide a LCD panel driving system adopting a panel driving apparatus compatible with a variety of panels having different specifications.
To achieve the first object of the present invention, there is provided a panel driving apparatus compatible with various types of panels for liquid crystal displays (LCDS) having different specifications, the apparatus comprising a microcontroller, a data converting unit, and a panel control unit, and a transmitting unit. The data converting unit is controlled by the microcontroller, receives composite data including color data and horizontal and vertical synchronization signals, and generates converted composite data and a clock signal. The panel control unit is controlled by the microcontroller, receives the converted composite data and the clock signal, and generates control signals for driving a panel and an internal data signal including the color data and the clock signal. The transmitting unit receives the internal data signal from the panel control unit and transmits the received internal data signal to the panel. It is preferable that the panel control unit comprises a scaler for scaling the converted composite data according to the specifications of the panel and a timing control portion for generating the control signals and the internal data signal.
To achieve the second object of the present invention, there is provided a panel driving system compatible with various types of panels for liquid crystal displays (LCDs) having different specifications, the panel driving system comprising a graphics card, a display device including a pane, and a panel driving apparatus for receiving composite data including color data and vertical and horizontal synchronization signals from the graphics card and generating control signals for driving the panel and a predetermined internal data signal. The panel driving apparatus includes: a microcontroller; a data converting unit controlled by the microcontroller, for receiving the composite data including the color data and the horizontal and vertical synchronization signals and generating converted composite data and a clock signal; a panel control unit controlled by the microcontroller, for receiving the converted composite data and the clock signal and generating the control signals for driving the panel, and the predetermined internal data signal including the color data and the clock signal; and a transmitting unit for receiving the predetermined internal data signal from the panel control unit and transmitting the received predetermined internal data signal to the panel.
It is preferable that the panel control unit comprises a scaler for scaling the converted composite data according to the specifications of the panel, and a timing control portion for generating the control signals and the internal data signal.
The microcontroller programs a variety of control parameters according to the specifications of the panel, stores the control parameters, and transmits the control parameters to the timing control portion.
The timing control portion preferably comprises an interface portion for receiving the color data, the vertical and horizontal synchronization signals, a data enable signal, and the control parameters from the microcontroller, and for generating first and second internal control signals and the internal data signal according to the specifications of the panel; a single control portion for receiving the first internal control signal and generating a single internal control signal for driving a panel having particular specifications; a double control portion for receiving the second internal control signal and generating a double internal control signal for driving another panel having different specifications; a data control portion for receiving the internal data signal and transmitting the received internal data signal to the transmitting unit; and a multiplexer for selecting one of the single internal control signal and the double internal control signal according to the specifications of the panel employed and generating the selected control signal as one of the control signals.
The system may further include a parallel-to-serial signal converting unit for receiving the control signals, for converting the received control signals to serial control signals, and for transmitting the serial control signals to the panel. In this case, the display device further comprises a serial-to-parallel signal converting unit for receiving the serial control signals, for converting the serial control signals to parallel control signals, and for transmitting the parallel control signals to the panel.